Area code 747 and area code 818 are California telephone area codes consisting largely of the San Fernando Valley of Los Angeles, California. They cover roughly two million people.

After the standardization of American telephone area codes, almost all of Los Angeles County used the 213 area code. Because the population and phone usage of the Los Angeles metropolitan area greatly increased during the 1980s and 1990s, the 213 area code was split into several new area codes, including the 818 and 310 area codes. The 818 area code entered service on January 7, 1984. Area code 626 was split from it on June 14, 1997.

In November 1999, it was proposed that "at some future date", a new 747 area code would split from 818, the new 747 serving Agoura, Canoga Park, Reseda, and Van Nuys. This proposal sat dormant until 2007, when the telephone industry and the California Public Utilities Commission began studying implementing this 818/747 split, or possibly an overlay of all of 818 with 747. Public hearings were held, and the overall public sentiment was for an overlay rather than the split, since they could retain the 818 area code for their existing telephone numbers. The new 747 area code would be used for numbers associated with new service.